diff --git a/lib/uri/rfc2396_parser.rb b/lib/uri/rfc2396_parser.rb
index b9e7b2b26e..e8e645d66c 100644
--- a/lib/uri/rfc2396_parser.rb
+++ b/lib/uri/rfc2396_parser.rb
@@ -315,13 +315,13 @@ def escape(str, unsafe = @regexp[:UNSAFE])
     #
     # :call-seq:
     #   unescape( str )
-    #   unescape( str, unsafe )
+    #   unescape( str, escaped )
     #
     # == Args
     #
     # +str+::
     #    String to remove escapes from
-    # +unsafe+::
+    # +escaped+::
     #    Regexp to apply. Defaults to self.regexp[:ESCAPED]
     #
     # == Description
@@ -329,7 +329,8 @@ def escape(str, unsafe = @regexp[:UNSAFE])
     # Removes escapes from +str+
     #
     def unescape(str, escaped = @regexp[:ESCAPED])
-      str.gsub(escaped) { [$&[1, 2].hex].pack('C') }.force_encoding(str.encoding)
+      enc = str.encoding
+      str.dup.force_encoding(Encoding::ASCII_8BIT).gsub(escaped) { [$&[1, 2].hex].pack('C') }.force_encoding(enc)
     end
 
     @@to_s = Kernel.instance_method(:to_s)
diff --git a/test/uri/test_parser.rb b/test/uri/test_parser.rb
index 757ac86c74..b9cf4b7e1a 100644
--- a/test/uri/test_parser.rb
+++ b/test/uri/test_parser.rb
@@ -45,4 +45,11 @@ def test_raise_bad_uri_for_integer
       URI.parse(1)
     end
   end
+
+  def test_unescape
+    p1 = URI::Parser.new
+    assert_equal("\xe3\x83\x90", p1.unescape("\xe3\x83\x90"))
+    assert_equal("\xe3\x83\x90", p1.unescape('%e3%83%90'))
+    assert_equal("\xe3\x83\x90\xe3\x83\x90", p1.unescape("\xe3\x83\x90%e3%83%90"))
+  end
 end